feat: Integrate TaskWarrior with config reading and optimized data

loading

- Read data.location from ~/.config/task/taskrc (supports
  TASKDATA/TASKRC env vars)
- Add get_overview() method to fetch tasks, projects, tags in one call
  (3→1 requests)
- Replace mock data with real TaskWarrior data
- Add logging with env_logger
- Improve tag logging output

Cargo.toml

@@ -7,7 +7,9 @@ license = "MIT OR Apache-2.0"
 [dependencies]
 chrono = { version = "0.4.42", features = ["serde"] }
 dirs = "6.0.0"
+env_logger = "0.11.0"
 gpui = "0.2.2"
+log = "0.4.22"
 serde = { version = "1.0.228", features = ["derive"] }
 serde_json = "1.0.147"
 taskchampion = "2.0.3"